The Bundesliga giants are smarting after consecutive defeats to Arsenal and Wolfsburg, with Subotic's injury following a collision with Ivica Olic on Saturday only compounding matters.

Subotic was substituted before the break at the Volkswagen Arena, with coach Jurgen Klopp explaining after the match the Serb had "probably torn the cruciate ligament", adding that the injury was "terrible news".

An MRI scan of the stopper's knee shortly afterwards confirmed Klopp's worst fears, as the club announced the stipulated recovery time to be six months.

"Neven Subotic is injured for the rest of the season," a statement read on Dortmund's official website.

"The central defender tore the posterior cruciate ligament and medial collateral ligament tear in his right knee. According to team doctor Markus Braun, the 25-year-old will be out for at least six months."

This news will come as a massive blow to BVB, with pivotal clashes against Bayern Munich and Napoli looming after the international break.

Klopp has relied heavily on his Mainz protege this term, handing him 16 appearances in all competitions so far.